Photovoltaic cells are devices that convert light energy into electricity via a light-absorbing material. The electricity can flow through wires to power electronic devices. A solar cell is a type of photovoltaic cell configured to capture and convert sunlight into electricity. Assemblies of solar cells can be arrayed into modules, which, in turn, can be linked together into solar arrays. These arrays can be used to generate electricity in places where a power grid is not available, such as in remote area power systems. Earth-orbiting satellites and space probes, remote radio telephone, and water pumping systems. In recent years, due to the increasing costs of generating electricity from fossil fuels, the demand for solar arrays to supplement home and commercial electrical power needs has increased.
However, most conventional photovoltaic cells only convert a small portion of the electromagnetic spectrum into electricity. For example, efficiencies vary from about 6 to about 10% for amorphous silicon-based photovoltaic cells to about 43% for multiple junction-based photovoltaic cells. In addition, mass producing the more efficient multiple junction photovoltaic cells to form photovoltaic arrays may be cost prohibitive. For example, the cost of mass producing a multiple junction photovoltaic cell may be as much as 100 times greater than the cost of producing the less efficient amorphous silicon-based cell. Most conventional photovoltaic cells are single-junction silicon cells that absorb a relatively narrow range of photon energies. As a result, much of the light that is incident on photovoltaic ceil is not absorbed. Thus, engineers and physicists have recognized a need for high-efficiency photovoltaic cells that can extract a larger portion of the electromagnetic spectrum.